Rotary pickling machine



Dec. 31, 1929. s. T. POWELL ROTARY PICKLING MACHINE Filed Feb. 10. 1928 inventor: Samuel TPowell,

His Attorne g Patented Dec. 31, 1929 UNITED STATES muse PATENT OFFICE SAMUEL T. POWELL, OF NEW KENSINGTON, PENNSYLVANIA, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK ROTARY PIGKLING MACHINE Application filed February 10, 1928 SeriaINo. 253,4e1.

In the manufacture of galvanized or enameled steel or iron pipe for electric conduits and other purposes, it is necessary to pickle the pipe in a suitable bath, such for example as one containing a limited amount of sulphuric acid, to remove the scale and otherwise clean the pipe prior to the galvanizing or enameling process.

The common practice is to place the pipes on end in a tank and submerge them in a suitable pickling agent and leave them there for a certain length of time to permit the pickling agent to perform its work. WVith such an arrangement the portions of the pickling agent which are within the pipes rapidly become weaker than the remaining and larger portion which surrounds the outsides of the pipes and hence works more slowly. This is particularly true of small diameter pipes. If the pipes remain long enough in the agent to be thoroughly pickled on the inside they are frequently overpickled on the outside which causes rifts. streaks or grooves in the outer walls.

This means that the pickling operation must be rather closely watched to prevent under-pickling on the inside of the pipes and over-pickling on the outside. On the average it requires about eight hours to pickle a 30 load of pipe in this type of apparatus.

' v Another practice which has been followed to a limited extent is to fasten a bundle of pipes on a rockin element which with the pipes is'submerged inthe pickling agent contained in a tank and slowly rock said element and the pipes thereon. This has the advantage over the first or stationary arrangement of affording some circulation-of the pickling agent which reduces the tendency to over-pickle certain parts, but since the pipes at no time during the operation are entirely removed from said agent, there is only a very limited movement of the agent within the pipes with practically no movement of the article to be pickled. F urthermore, a machine suitable for this purpose presents certain practical difliculties in the way of loading and unloading, has to be of relatively small capacity, and requires considerable time for each operating cycle, the average being about six hours.

My invention has for its object to overcome the difficulties in pickling which have heretofore existed and specifically those mentioned above, and to provide an improved machine in which the time consumed in the cycle of operation is decreased, in

which the pipes are permitted to fall on'one another with a pounding and abrasive action to dislodge the scale both inside and outside the pipe, and in which there is a complete washing action of the agent on both the insides and outsides of the pipes and at the same time a complete circulation and mixing of the pickling agent main tained so that its action is uniform over all surfaces of the pipes.

For a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto.

In the attached drawing which is illustrative of one of the embodiments of my invention, Fig. 1 is a plan View of a pickling machine; Fig. 2 is an end view thereof with certain of the parts broken away; Fig. 3 is a perspectiveview of one of the means for confining the pipe, and Fig. 4 is a somewhat diagrammatic view showing how the pipes tumble about as the rotor revolves and thus pound off the scale.

' 5 indicates a tank of suitable construction generally lead lined, the bottom portion of which conforms more or less closely to therotating structure so as to avoid the use of an excess quantity of the pickling agent and also to eliminate corners or dead spots where the agent would be liable to become stagnant. Any suitable pickling agent may be used; one containing about 5% sulphuric acid will give satisfactory results.

Mounted above the tank with a portion thereof submerged in the pickling agent is a rotor or cage comprising a shaft 6 having a suitablenumber of spiders 7 thereon to carry the material to be pickled, two such spiders being shown in the present illustration of my invention and located near the opposite end walls of the tank, The shaft,

spiders and associated parts which dip into the pickle are made of or are covered with anti-acid metal of any suitable character. The spiders each have a number of arms 8 which extend radially outward from the shaft. The number may be varied to suit the requirements but I have found six arms to be satisfactory for my purpose. The sides of each adjacent pair of arms define the walls of a segmentalpocket 9 in which the pipes 10 to be treated are located. For simplicity of illustration the pipes are shown as being of rather large diameter. As an illustration but not as a limitation of my invention, each segmental pocket is designed to receive from four and one-half to five tons of pipe making a total load on the rotor of from twenty-seven to thirty tons. The pockets are only partly filled with pipes as it is important that they be permitted to roll about and fall one on the other as the rotor slowly turns. The tumbling of the pipes in each pocket as the rotor slowly turns causes pounding and abrasive actions which dislodge the scale both from the interior and exterior of the pipes, and due to the fact that each group of pipes successively enters and leaves the pickle, a thorough washing is effected. By preference, the same number of pipes is located in each of the pockets so that the rotor as a whole is balanced. As the pipes enter the pickle they are filled and as they leave they are drained, there being quite a rapid rush of the pickle from the pipes as they rise above the level of the agent in the tank.

The use of relatively thick arms for the spider aside from the matter of strength serves to afford spacers of substantial size between groups of pipes and through the spaces thus formed the pickle and foreign matter such as scale from the pipes is free to flow and thus facilitate the washing operation and prevent the pocketing of scale which might otherwise retard the pickling operation. Further, the separation of one group of pipes from the other affords spaces for the slings by means of which each segmental load or group of pipes can be installed and removed, and the slings withdrawn. The slings used may be of any suitable construction such as are in common use in factories. Due to the weight of the pipes, it is desirable to have a power-d-riven crane for handling them.

This invention contemplates automatic means by which loading and unloading can be accomplished without the use of power operated crane or sling. This can be accomplished by revolving the rotor to a position which will permit of dumping the load into a suitable receptacle after which it is further rotated until the emptied pocket or space is in position to receive a load of pipe or other material to be pickled.

With such an arrangement it is necessary to restrict the endwise movements of the pipes and this is done by providing a pair of end shields 11 for each segmental pocket. These shields are attached to the spider arms by any suitable means, or they may be integral therewith. In addition to limiting the endwise movements of the pipes these end shields also act as paddle wheels to agitate the pickling agent and assist in keeping it thoroughly mixed.

In order to confine each group of pipes within a segmental pocket and at the same time permitof their being inserted and withdrawn from place, each spider arm is connected to its neighbor by a swinging bar or member 12 which is hinged to one arm by the pin 13 and is locked or held in a clevis it at the outer end by a suitable pin. These members are comparatively heavy since at times they have to sustain the load of pipein the segmental pocket, and also have to withstand the shock due to the falling pipes as the rotor Or cage turns. The particular means for mounting and fastening the memhers is not material so long as they are of a substantial nature. They are preferably simple so as to facilitate loading and unloading.

The shaft of the rotor is supported at its ends by bearings 15 which are located on suitable pedestals and these bearings are preferably outside of the tank and protected by shields from the pickle. The shields 11 will sutlice for this purpose. On one end of the shaft is a rather large gear 16 which is driven by a small pinion 17 so as to get a suitable speed reduction. The pinion is mounted on a shaft 18 which in turn is driven by a large worm wheel 19 mounted in a casing. This wheel is driven by a worm on the shaft of the electric motor 20. Due to this double gear reduction a very low speed of rotation of the rotor or case is obtained and this with a motor of relatively low horsepower.

In loading and unloading the machine the rotor is turned to a position where one of the segmental pockets is in a substantially vertical position after which the pair of members 12 for the pocket are each released at one end and swing outwardly about its pivot or hinge. By the use of suitable automatic means, such as slings, the pipes which have been treated in the pickling agent are removed, and a second lot substituted after which the members are returned to their normal positions and locked in place. The rotor is then turned to bring a second pocket in a vertical position when the loading operation is repeated, and so on until all the pockets are filled. I have found that with my improved machine the pickling may be accomplished in four hours against six hours for the oscillating or rocking type and eight hours for the stationary type, and moreover, the results are superior.

Referring to Fig, 4, 21 indicates the approximate level of the pickling agent in the tank. As the rotor slowly turns (I have found one to three revolutions per minute to be satisfactory), the pipes contained in the upper right hand pocket by sliding and falling assume the approximate positions inclicated in the central right hand pocket and thereafter they assume the approximate positions indicated in the lower right hand pocket. In general, the pipes move radially outward on the descending portion of the rotor or carrier movement and radially inward on the ascending portion of the rotors movement. Continued movement of the rotor causes the pipes to further change their relative positions as indicated on the left hand side of the vertical center. It is to be particularly noted that some of the pipes in moving from one position to another slide and others fall somewhat after the fashion of articles in a tumbling barrel. This abrasive and pounding action dislodges scale from both the inside and outside of the pipes. As the pipes slowly enter the pickle the latter flows into them from both ends as well as over the outer surfaces, and as they leave the pickle the latter flows out of them with considerable force and carries with it such scale as has been dislodged by the pounding action of one tube on the others. The rotation of the pipes and the rotor agitates the pickling agent thereby ensuring a uniform mixture at all times. This is greatly assisted by the fact that as each pipe rises above the level of the pickle there is a flow of pickle from within the pipe toward both ends of the tank. Pipes pickled in this machine show the inside as well as the outside to be thoroughly and uniformly cleaned with the inside having the generally bright appearance of a gun barrel.

Should it be desired to pickle shorter or longer pipes or other articles the rotor or carrier may be modified to receive them or special holding devices may be provided, such as cages for sheets, rods, angles, wire, structural shapes, etc.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

IVhat I claim as new and desire to secure by Letters Patent of the United States is 1. In a pipe-pickling machine, the combination of a tank containing a pickling agent, a rotor supported in such manner that a portion thereof is submerged in the agent, said rotor comprising a shaft and a pair of spaced spiders, each of which has radially-disposed arms which define pockets in which the pipe is located, detachable means for connecting the outer ends of the arms, means for limiting the en'dwise movements of the pipes within the pockets, and means for rotating the rotor.

2. In a pipe-pickling machine, the combination of a tank containing a pickling agent, a rotor comprising a shaft and spaced groups of radially disposed arms mounted thereon, which define circumferentially arranged pockets open at their outer ends, a member which is hinged to each of the arms at one end and has a means at the other end for securing it to an adjacent arm, bearings outside of the walls of the tank which support the rotor above the tank and permit the portions of the rotor below the shaft to dip into the tank, and means for slowly rotating the shaft.

3. In a pipe-pickling machine, the combination of a tank containing a pickling agent, a shaft extending across the tank, bearings for the shaft, radially extending arms carried by the shaft which form pockets in which the pipes are supported at their ends and retained in independent groups, the pipes in each group being so positioned with respect to the shaft that they are successively submerged and removed from the pickling agent as the shaft revolves, means forming removable covers for said pockets, other means which limit the longitudinal movements of the pipes while permitting them to freely move in a generally radial direction as the rotor turns, and power-actuated means connected to the shaft for rotating it.

In witness whereof, I have hereunto set my hand this 8th day of February, 1928.

SAMUEL T. POWELL. 

